Кузьменко, А.Г., and Б.М. Сабадаш. “ Solution for Summer-Variational Methods to Asses”. Problems of Tribology 73, no. 3 (June 18, 2015): 80–85. Accessed March 29, 2024. https://tribology.khnu.km.ua/index.php/ProbTrib/article/view/396.